Corona Virus Disease 2019 (COVID-19) is a new illness caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing number of confirmed cases and the accumulating clinical data, a broad spectrum of neurological complications has been reported in the literature, including encephalopathy, stroke, Guillain-Barré syndrome, meningo-encephalitis, acute necrotizing hemorrhagic encephalopathy, and inflammatory central nervous system syndromes. Here, we describe the case of a 38-year-old woman presenting with longitudinally extensive transverse myelitis, revealed by bilateral lower limb weakness, decreased sensation below the Th4 level and urinary retention, and occuring 15 days after she had been diagnosed with COVID-19.Omsk hemorrhagic fever virus (OHFV) is the etiological agent of Omsk hemorrhagic fever, a disease described in the 1940s in Western Siberia. However, until now, it has been represented in GenBank by just four complete genome sequences, which do not reflect the real genetic diversity of the virus in nature. In this study, we analyzed the molecular variability and genetic structure of OHFV based on 20 complete genome sequences, fifteen of which were obtained for the first time. All these sequences belong to virus strains isolated at different times from three regions of Western Siberia. The results suggest that the genetic diversity of OHFV is significantly wider than previously thought and is represented by at least three subtypes, rather than two. This broadens our understanding of the evolutionary history of OHFV. Also, it is argued that the OHFV reference strain Bogoluvovska (NC_005062) is actually a Kubrin strain and that either cross-contamination or a laboratory error was the cause of this.The genus Borrelia encompasses 50 spirochetal species, several of which are pathogenic and have been detected in a wide range of mammals, especially rodents and cervids. Although the order Chiroptera is the second most diverse mammalian order, and borreliosis represents a human and veterinary health problem in endemic countries, few studies have previously reported infections of Borrelia in these flying mammals. For this reason, the aim of the present study was to detect the presence of, and to analyze the diversity of Borrelia species in several bat species from Mexico. A total of 69 bats belonging to 11 species were collected and molecular detection of Borrelia was performed by amplifying three genes using specific primers. Only five individuals of four bat species (Saccopteryxbilineata, Choeroniscus godmani, Sturnira parvidens and Lasiurus cinereus) tested positive for Borrelia DNA. We now show the first Borrelia record in Mexican bats from two different ecosystems, where previously several potential vector species of the genus Ixodes and Ornithodoros had been reported. https://www.selleckchem.com/products/iox1.html The Borrelia sequences obtained from the bats revealed two new putative lineages, one from the relapsing fever group and the second one belonging to the Borrelia burgdorferi s.l. complex, both of which are related to zoonotic species. These results highlight the importance of bats as potential hosts of Borrelia, and the imperative need of active surveillance in flying mammals in order to understand their potential role in the life cycle of this bacteria genus.The genus Rickettsia encompasses 35 valid species of intracellular, coccobacilli bacteria that can infect several eukaryotic taxa, causing multiple emerging and re-emerging diseases worldwide. This work aimed to gather and summarise the current knowledge about the genus Rickettsia in Mexico, updating the taxonomy of the bacteria and their hosts by including all the records available until 2020, to elucidate host-parasite relationships and determine the geographical distribution of each Rickettsia species present in the country. Until now, 14 species of Rickettsia belonging to four groups have been recorded in Mexico. These species have been associated with 26 arthropod species (14 hard ticks, three soft ticks, two sucking lice, and seven fleas) and 17 mammal species distributed over 30 states in Mexico. This work highlights the high biological inventory of rickettsias for Mexico and reinforces the need to approach the study of this group from a One Health perspective.Rhipicephalus microplus is responsible for high economic losses in livestock and its control has become difficult due to the establishment of tick populations resistant to commercial acaricides. This study aimed to evaluate the in vitro larvicidal effect of the alkaloids berberine and piperine, and also to investigate their inhibitory mechanisms against the acetylcholinesterase enzyme. The effects of the alkaloids on larvae were observed through the immersion test at the following concentrations 1.5; 3; 6; 12; 16 and 24 mM. Berberine and piperine presented larvicidal activity greater than 95 %, not differing from 100 % for the positive fipronil control (p &gt; 0.05). Of the two alkaloids, piperine had a lower effective concentration (EC), with an EC50 of 6.04 mM. The acetylcholinesterase enzyme used in the study was obtained from R. microplus larvae (RmAChE) and the anticholinesterase activity was determined spectrophotometrically. The highest anticholinesterase activity, measured as inhibition concentration (IC), was observed for berberine (IC50 = 88.13 μM), while piperine showed lower activity (IC50 &gt; 200 μM). Docking studies in RmAChE, followed by 10 ns molecular dynamics simulation, suggest that berberine stabilizes the RmAChE at lower Root-Mean-Square Deviation (RMSD) than Apo protein. Few hydrogen-bond interactions between berberine and RmAChE residues were balanced by hydrophobic and π-type interactions. Berberine fills preferentially the peripheral anionic site (PAS), which correlates with its non-competitive mechanism. These results suggest that berberine and piperine alkaloids have an in vitro acaricidal action on R. microplus larvae, and the likely mechanism of action of berberine is related to RmAChE inhibition when accessing the PAS residues. These findings could help the study of new natural products that could inhibit RmAChE and aid in the development of new acaricides.